Hiroki Sekine1, Masayuki Yamamoto2, Hozumi Motohashi3. 1. Department of Gene Expression Regulation, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan. 2. Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan. 3. Department of Gene Expression Regulation, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan. hozumim@med.tohoku.ac.jp.